<!DOCTYPE html>
<html>
<head>
<title>HtmlFormatTest.html</title>

<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="this is my page">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">

<!--<link rel="stylesheet" type="text/css" href="./styles.css">-->

</head>
<style type="text/css">
.div{
	height:100px;
	width:100px;
	background-color:red;
}
</style>
<body>
	<div id="div" class="div">hello,world!</div>
	<button onclick="demo()">按钮</button>
<script>
function demo(){
	document.getElementById("div").style.background="blue";
}
</script>
</body>
</html>
